Also dont forget that most speedo's are out, i experience this sort of thing a lot in a truck that has a speedo the is spot on, its amazing how many times i go up the hume in the 110 zone doing 100 (max allowed by a truck in australia) and im overtaking cars.
would not be surprised if you speedo is saying 60 and your actually doing 55 or less, then of course you are constantly speeding up and slowing, and even worse you are speeding up and braking, i know that would piss me off.
its also amazing how you were so scared but were willing to speed up and brake but not willing to brake and pull in behind the car beside you.
As some one who spends a lot of time on the road if i was sitting behind you it would look like your trying to piss me off, then when he did it back to you you got pissed off, funny how that works.
Also if you had have been watching your mirrors you would have seen him coming up behind you and had time to pull in front or behind the car beside you, might cost you an extra few seconds but would have saved you in the end.